Completions in low pressure formations involve a risk of fluid loss into the formation. In these instances the hydrostatic pressure from the liquid column in the production string is higher than the formation pressure. A fluid loss valve selectively keeps the fluid in the production string from flowing into the formation and potentially decreasing its subsequent ability to produce hydrocarbons from the formation. On the other hand, when the formation needs to be produced, the valve must be opened to allow the formation a path to the surface through the production tubing.
In the past, packer assemblies have come with valves that can be opened with production string manipulation. In some cases the manipulation involved up and down cycling to operate a downhole j-slot mechanism to change the position of a valve associated with a packer to either and open or a closed position with an exit from the j-slot being available to pull the string out of the hole. One example of such a design is U.S. Pat. No. 5,826,652. Another mechanically manipulated valve for controlling fluid loss involves a stinger on the bottom of the production string that can be engaged to a sliding sleeve valve to set it in an open or closed position with string manipulation. This product is available from Baker Oil Tools under the product name Reservoir Control Valve Product Family H68406. J-slot valves of various types are illustrated in U.S. Pat. Nos. 5,529,126; 6,889,771 and 7,090,020.
In both instances, the mechanical string manipulation that it takes to operate these valves requires the use of a rig. The cost of a rig is very high and the present invention allows the provision of a fluid loss valve that can be operational to prevent loss to the formation and can then be disabled as the formation is allowed to come into the production string. The positions can be achieved with pressure rather than tubing string manipulation. A flapper and a sliding sleeve provide a dual closure to prevent fluid loss. Pressure operation manipulates a sleeve to an open position and the formation coming in moves the flapper out of the way. These and other features of the invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and associated drawings that appear below, while recognizing that the full scope of the invention is measured by the appended claims.